JP2014052494A - Image display device, control method of image display device, control program of image display device, and recording medium recording control program - Google Patents

Abstract

The present invention suppresses deterioration of display quality.
When a control device detects an unintended black image (YES in S102), a backlight immediately before detection of the black image until a predetermined time elapses (NO in S104, S108). A step of notifying the target luminance value and the correction amount of the image brightness (S112), a step of correcting the image based on the notified correction amount of the luminance of the image (S114), and the corrected image by liquid crystal A program is executed including a step of displaying on the panel (S116) and a step of controlling the backlight based on the notified backlight brightness target value (S118).
[Selection] Figure 2

Description

  The present invention relates to a technique for adjusting the luminance of a light source and the luminance of an image according to the brightness of the image.

  For example, in Japanese Patent Application Laid-Open No. 2007-018013 (Patent Document 1), when the luminance of the input signal is high, the amount of light is increased from the illumination light source, and when the luminance of the input signal is low. A display device that reduces the amount of light from an illumination light source is disclosed. Furthermore, Japanese Patent Application Laid-Open No. 2008-309908 discloses an image display device that increases the level of video signal or the luminance level when the level of video signal is low for a certain time.

JP 2007-018013 A JP 2008-309908 A

  By the way, in an image display device including a liquid crystal panel and a light source (for example, a backlight), when the brightness of an image to be displayed is low, the brightness of the light source is lowered and the change of increasing the brightness of the image is performed slowly. A technique for suppressing an increase in power consumption in a light source without greatly changing the appearance in the above is known.

  However, when a bright image is displayed and a black image irrelevant to the previously displayed image is displayed for a certain period of time and then returns to a bright image display, the black image is displayed. From the point in time, the luminance of the light source is decreased and the luminance of the image is increased. Therefore, when the display of a bright image is restored, the luminance of the light source is increased with the passage of time from the time of the restoration, and the luminance of the image is lowered. As a result, when the display of a bright image is restored, the image appears darker than before the black image is displayed, and flickering may occur and display quality may deteriorate.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an image display device that suppresses deterioration of display quality, a control method for the image display device, a control program for the image display device, and control thereof. It is to provide a recording medium on which a program is recorded.

  An image display device according to an aspect of the present invention includes a liquid crystal panel that displays an image, a light source that illuminates the liquid crystal panel, and a control device that corrects the luminance of the light source and the luminance of the image. When a black image is detected from a plurality of images in a case where a plurality of images are continuously displayed, the control device determines the brightness of the light source and the image until a predetermined time elapses after the black image is detected. Suppresses brightness correction.

  Preferably, when the control device displays a plurality of images continuously, when the black image is detected and the magnitude of the difference in brightness between the black image and the image detected immediately before is larger than a threshold value The correction of the luminance of the light source and the luminance of the image is suppressed until a predetermined time elapses after the black image is detected.

  More preferably, the control device cancels the suppression of the correction of the luminance of the light source and the luminance of the image when the detection of the black image continues for a predetermined time or more.

  More preferably, the control device corrects the brightness of the image to increase while decreasing the brightness of the image while decreasing the brightness of the light source, and increases the brightness of the image while increasing the brightness of the light source as the brightness increases. It corrects so that it may decrease.

  More preferably, the predetermined time is set so that no flicker occurs due to the correction of the luminance of the light source based on the detection of the black image and the luminance of the image.

  More preferably, the control device determines whether or not the image is a black image based on the histogram of the image.

  An image display apparatus control method according to another aspect of the present invention is an image display apparatus control method including a liquid crystal panel that displays an image and a light source that illuminates the liquid crystal panel. In this control method, the step of correcting the luminance of the light source and the luminance of the image, and when displaying a plurality of images continuously, when a black image is detected from a plurality of images, the black image is detected. Suppressing the correction of the luminance of the light source and the luminance of the image until a predetermined time has elapsed.

  A control program for an image display device according to still another aspect of the present invention is a control program for an image display device including a liquid crystal panel that displays an image and a light source that illuminates the liquid crystal panel. This control program detects a black image when a computer detects a black image from a plurality of images in a step of correcting the luminance of the light source and the luminance of the image and displaying a plurality of images continuously. And a step of suppressing the correction of the luminance of the light source and the luminance of the image until a predetermined time has elapsed.

  A recording medium according to still another aspect of the present invention is a recording medium that records the control program for the image display device.

  According to the present invention, in the case where a plurality of images are continuously displayed, when a black image is detected from the plurality of images, the brightness of the light source and the image until a predetermined time elapses after the black image is detected. By suppressing the correction of the luminance, it is possible to suppress the occurrence of flickering due to the luminance of the light source based on the detection of the black image and the luminance of the image. Therefore, it is possible to provide an image display device that suppresses deterioration of display quality, a control method for the image display device, a control program for the image display device, and a recording medium on which the control program is recorded.

1 is a schematic block diagram of an image display device according to the present embodiment. It is a flowchart which shows the control structure of the program performed with the image display apparatus which concerns on this Embodiment. It is a timing chart which shows operation | movement of the control apparatus in case this invention is applied. It is a timing chart which shows operation | movement of the control apparatus when this invention is not applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  As shown in FIG. 1, the image display device 1 according to the present embodiment includes a control device 2, a display driver 3, a liquid crystal panel 4, and a backlight 5.

  Display data is input to the control device 2. The display data includes data for displaying one frame image on the liquid crystal panel 4. The display data is read from a storage device (not shown) and input to the control device 2, for example. The storage device is a rewritable recording medium such as a memory or a hard disk. The memory is, for example, a NAND flash memory.

  The control device 2 generates a control signal based on the input display data and transmits the generated control signal to the display driver 3 and the backlight 5. The display driver 3 applies a voltage to the liquid crystal panel 4 based on a control signal received from the control device 2.

  The liquid crystal panel 4 displays an image upon application of a voltage by the display driver 3. The backlight 5 is a light source that illuminates the liquid crystal panel 4 based on a control signal received from the control device 2.

  Such an image display device 1 may be used for a mobile terminal such as a smart phone terminal or a tablet terminal, a monitor mounted on a laptop personal computer, a stationary monitor, a liquid crystal television, or the like.

  The control device 2 corrects the brightness BL of the backlight 5 and the brightness of the image included in the display data. The control device 2 corrects the brightness BL of the backlight 5 and the brightness of the image without greatly changing the appearance of the image (that is, maintaining the brightness of the entire image).

  For example, the control device 2 corrects the brightness of the image to increase while decreasing the brightness BL of the backlight 5 as the brightness of the image is smaller (the darker the image is). Alternatively, for example, the control device 2 corrects the brightness of the image to decrease while increasing the brightness BL of the backlight 5 as the brightness of the image increases (the brighter the image).

  The control device 2 increases or decreases the brightness of the image by changing each pixel value of the image. The control device 2 suppresses the occurrence of flickering by gently changing the brightness BL of the backlight 5 and the brightness of the image.

  Assume that the image display device having such a configuration displays a plurality of images continuously. In this case, when a bright image is displayed, a black image irrelevant to the images displayed so far is displayed for a certain period of time, and after returning to the display of the bright image, the brightness BL of the backlight 5 and the image In some cases, flicker may occur due to luminance correction, and display quality may deteriorate. This is because the brightness of the light source is reduced from the time when the black image is displayed, and the brightness of the light source is increased from the time of the return because the display of the bright image is restored after correction so that the brightness of the image is increased. This is because correction is made so that the luminance of the image is lowered. Such a phenomenon may occur, for example, when an activation image is displayed when the terminal is activated when the image display device is used for the terminal.

  In the present embodiment, when the control device 2 continuously displays a plurality of images, when a black image is detected from the plurality of images, a predetermined time elapses after the black image is detected. This is characterized in that the correction of the brightness BL of the backlight 5 and the brightness of the image is suppressed until it is done.

  The control device 2 includes an image processing unit 30, an image analysis unit 32, a backlight control unit 34, a black image detection unit 36, and a timer unit 38.

  The image processing unit 30 corrects the luminance of the image included in the display data based on the correction amount C of the luminance of the image notified from the image analysis unit 32, and outputs the corrected image to the display driver 3. Specifically, when the correction amount C of the luminance of the image is notified from the image analysis unit 32, the image processing unit 30 changes the luminance of the image by the notified correction amount C.

  The image processing unit 30 gradually changes the luminance of the image by the notified correction amount C. For example, the image processing unit 30 sets an upper limit value for the amount of change in the luminance of the image, and the correction amount of the luminance of the image approaches the correction amount C notified from the image analysis unit 32 as time elapses. The luminance may be changed stepwise or continuously.

  Alternatively, for example, the image processing unit 30 multiplies the difference between the luminance of the image determined immediately before and the luminance of the image changed by the notified correction amount C by a value smaller than 1 for the current image. The brightness may be determined.

  The image analysis unit 32 calculates the target value of the brightness BL of the backlight 5 and the correction amount C of the brightness of the image according to the brightness of the image included in the display data. For example, the image analysis unit 32 converts the image into a grayscale image of 256 gradations using a known method, and creates a histogram indicating the brightness of each pixel and its distribution based on the brightness of each pixel. The image analysis unit 32 calculates a target value of the brightness BL of the backlight 5 and an image brightness correction amount C for the image included in the display data based on the created histogram.

  The image analysis unit 32 sets the target value of the brightness BL of the backlight 5 and the correction amount C of the brightness of the image so that the brightness BL of the backlight 5 is increased and the brightness of the image is decreased as the image is brighter. calculate.

  In addition, the image analysis unit 32 decreases the brightness BL of the backlight 5 as the image is darker and increases the target value of the brightness BL of the backlight 5 and the brightness of the image so as to increase the correction amount C of the brightness of the image. The correction amount C is calculated.

  For example, in the image included in the display data, the image analysis unit 32 determines that the image is brighter as the number of pixels that exceed the predetermined brightness is larger or the number of pixels that are lower than the predetermined brightness is smaller. Then, the target value and the correction amount C may be calculated so as to increase the luminance BL of the backlight 5 and decrease the luminance of the image.

  Alternatively, for example, in the image included in the display data, the image analysis unit 32 is a darker image as the number of pixels exceeding the predetermined brightness is smaller or as the number of pixels lower than the predetermined brightness is larger. And the target value and the correction amount C may be calculated so as to decrease the brightness BL of the backlight 5 and increase the brightness of the image.

  Note that the amount of change in the brightness BL of the backlight 5 and the amount of correction C for the brightness of the image are values having a correlation so that the appearance of the image does not change significantly. Further, the predetermined brightness is not particularly limited.

  The image analysis unit 32 notifies the backlight control unit 34 of the calculated target value of the brightness BL of the backlight 5. Further, the image analysis unit 32 notifies the image processing unit 30 of the calculated brightness correction amount C of the image.

  In the present embodiment, when the black image detection unit 36 notifies the detection of an unintended black image, the image analysis unit 32 determines the brightness of the backlight 5 until a predetermined time elapses after receiving the notification. Suppresses correction of BL and image brightness.

  For example, when the detection of an unintended black image is notified from the black image detection unit 36, the image analysis unit 32 calculates the target value of the brightness BL of the backlight 5 calculated based on the image immediately before the detection of the black image. May be notified to the backlight control unit 34, and the image luminance correction amount C calculated based on the image immediately before the detection of the black image may be notified to the image processing unit 30.

  Alternatively, for example, when the detection of an unintended black image is notified from the black image detection unit 36, the image analysis unit 32 notifies the backlight control unit 34 that the luminance BL of the backlight 5 is to be maintained. The image processing unit 30 may be notified that the image brightness correction amount C is maintained.

  The image analysis unit 32 cancels the suppression of the correction of the luminance BL of the backlight 5 and the luminance of the image when the black image detection unit 36 notifies that the detection of the black image continues for a predetermined time or longer. To do. That is, the image analysis unit 32 calculates the target value of the brightness BL of the backlight 5 and the correction amount C of the brightness of the image based on the detected black image.

  The backlight control unit 34 generates a control signal for controlling the luminance BL of the backlight 5 based on the target value of the luminance BL of the backlight 5 notified from the image analysis unit 32, and uses the generated control signal. Transmit to the backlight 5.

  Specifically, when the target value of the luminance BL of the backlight 5 is notified from the image analysis unit 32, the backlight control unit 34 is configured so that the luminance BL of the backlight 5 becomes the notified target value. The brightness BL of the backlight 5 is controlled.

  The backlight control unit 34 gradually changes the luminance BL of the backlight 5 until the luminance BL of the backlight 5 reaches the target value of the notified luminance BL of the backlight 5. For example, the backlight control unit 34 sets an upper limit value for the amount of change in the brightness BL of the backlight 5 and sets the brightness BL of the backlight 5 so that the brightness BL of the backlight 5 approaches the target value as time elapses. Change in steps or continuously.

  The black image detection unit 36 determines whether or not the image included in the display data is an unintended black image, and notifies the image analysis unit 32 of the detection of the black image when determining that the image is an unintended black image. . For example, the black image detection unit 36 may determine that the image included in the display data is a black image when the pixel values of all the pixels of the image included in the display data are values indicating black. Alternatively, the black image detection unit 36 may determine that the image included in the display data is a black image when the number of pixels having a pixel value indicating black is greater than the threshold value. Alternatively, the black image detection unit 36 may determine that the image included in the display data is a black image when the number of pixels lower than the predetermined brightness is greater than the threshold value. The threshold value or the predetermined brightness may be determined in consideration of noise superimposed on the image included in the display data.

  Furthermore, when a black image is detected, the black image detection unit 36 detects an unintended black image if the magnitude of the difference in brightness between the black image and the image immediately before the detection of the black image is larger than a threshold value. It is determined that The threshold value is a value for determining, for example, a case where a black image unrelated to the immediately preceding image is inserted while a bright image is displayed.

  When the black image detection continues for a predetermined time or more based on the elapsed time notified from the timer unit 38, the black image detection unit 36 notifies the image analysis unit 32 to that effect.

  The timer unit 38 resets (initializes) the counter value to an initial value when an unintended black image is not detected. When an unintended black image is detected, the timer unit 38 increases the value of the counter as time passes when the counter is reset to the initial value. The timer unit 38 stops increasing the counter value when the counter value becomes a value corresponding to a predetermined time. The timer unit 38 notifies the black image detection unit 36 of the counter value every time the counter value is increased.

  The processes in the image processing unit 30, the image analysis unit 32, the backlight control unit 34, the black image detection unit 36, and the timer unit 38 are realized by hardware or software executed by the CPU. Such software is stored in a storage device. The software may be stored in a memory card or other storage medium and distributed as a program product. Alternatively, the software may be provided as a program product that can be downloaded by an information provider connected to the so-called Internet. Such software may be read from the storage medium by an IC card reader / writer or other reading device, or may be stored in the form of a program executable on the storage device after being downloaded.

  With reference to FIG. 2, a control structure of a program executed by control device 2 of image display device 1 according to the present embodiment will be described.

  In step (hereinafter, step is described as S) 100, control device 2 inputs display data to image processing unit 30, image analysis unit 32, and black image detection unit 36.

  In S102, the black image detection unit 36 determines whether or not an unintended black image is detected based on an image included in the display data. If an unintended black image is detected (YES in S102), the process proceeds to S104. If not (NO in S102), the process proceeds to S106.

  In S104, the timer unit 38 starts incrementing (counting) the counter value when it has been initialized (that is, when the counter value is the initial value), and counts after a predetermined time has elapsed. Stop. In S106, timer unit 38 initializes the value of the counter.

  In S108, the timer unit 38 determines whether the count is stopped. If counting by timer unit 38 has stopped (YES in S108), the process proceeds to S110. If not (NO in S108), the process proceeds to S112.

  In S110, the image analysis unit 32 calculates the target value of the brightness BL of the backlight 5 based on the brightness of the input display data image, and notifies the backlight control unit 34 of the calculated target value. Then, the correction amount C of the luminance of the image is calculated, and the calculated correction amount C is notified to the image processing unit 30.

  In S112, the image analysis unit 32 notifies the backlight control unit 34 of the target value of the brightness BL of the backlight 5 immediately before the black image is detected, and corrects the brightness of the image immediately before the black image is detected. The amount C is notified to the image processing unit 30. In S114, the image processing unit 30 corrects the luminance of the image included in the display data based on the correction amount C of the luminance of the image notified from the image analysis unit 32.

  In S116, the image processing unit 30 displays the corrected image on the liquid crystal panel 4. In S118, the backlight control unit 34 controls the luminance BL of the backlight 5 based on the target value of the luminance BL of the backlight 5 notified from the image analysis unit 32.

  The operation of the control device 2 of the image display device 1 according to the present embodiment based on the above-described structure and flowchart will be described with reference to FIGS. 3 and 4.

<When the present invention is applied>
As shown in FIG. 3, for example, a case is assumed where a bright image is input to the control device 2 as display data. The control device 2 inputs the display data to the image processing unit 30, the image analysis unit 32, and the black image detection unit 36 (S100).

  If no black image is detected (NO in S102), timer unit 38 initializes the counter value (S106). The image analysis unit 32 calculates the target value of the luminance BL of the backlight 5 and the correction amount C of the luminance of the image based on the brightness of the image included in the display data, and calculates the calculated luminance BL of the backlight 5. The target value is notified to the backlight control unit 34, and the calculated image brightness correction amount C is notified to the image processing unit 30 (S110).

  At this time, since the image included in the display data is a bright image, the target value of the brightness BL of the backlight 5 is the upper limit value BL (1), and the correction amount C of the brightness of the image is the lower limit value C (0). . The image processing unit 30 corrects the brightness of the image based on the notified correction amount C (S114), and displays the corrected image on the liquid crystal panel 4 (S116). The backlight control unit 34 controls the backlight 5 based on the notified target value of the brightness BL of the backlight 5 (S118). As a result, the luminance BL of the backlight 5 is maintained at the upper limit value (1) and the correction amount C of the luminance of the image is maintained at the lower limit value C (0) until time T (1) when a bright image is displayed. The Rukoto.

  When the image input as the display data is a dark image (not a black image), the target value of the luminance BL of the backlight 5 is lower than the upper limit value BL (1) of the luminance of the backlight 5. . Further, the image luminance correction amount C is higher than the lower limit C (0) of the image luminance correction amount C.

  As a result, after time T (1), the brightness BL of the backlight 5 decreases with the passage of time until the target value is reached at time T (2). Furthermore, the correction amount C of the luminance of the image increases with the passage of time from the time T (1) to the correction amount C notified at the time T (2). Since the brightness BL of the backlight 5 is reduced and the correction amount C of the brightness of the image is increased, the power consumption in the backlight 5 can be reduced without greatly changing the appearance of the image by the user.

  When the brightness BL of the backlight 5 reaches the notified target value at time T (2) and the brightness correction amount C of the image reaches the notified correction amount, the brightness BL of the backlight 5 is reached. In addition, the correction amount C of the luminance of the image is maintained.

  When the image input as the display data is brighter than the previous image at time T (3), the target value of the brightness BL of the backlight 5 is determined based on the brightness of the display data at time T ( 1) to a value higher than the target value of the brightness BL of the backlight 5 determined in the time T (3). Further, the image luminance correction amount C is lower than the image luminance correction amount C determined in the time T (1) to the time T (3).

  As a result, from time T (3) to time T (4), the brightness BL of the backlight 5 increases with time, while the image brightness correction amount C decreases.

  When the brightness BL of the backlight 5 reaches the notified target value and the brightness correction amount C of the image reaches the notified correction amount at time T (4) to time T (5), The correction amount C of the brightness BL of the backlight 5 and the brightness of the image is maintained.

  When a black image is input as display data at time T (5) (S100), it is determined that an unintended black image has been detected because the difference in brightness from the previous display data image is lower than the threshold value. Not performed (NO in S102).

  At this time, since the image input as the display data is a black image, the target value of the luminance BL of the backlight 5 is the lower limit value BL (0), and the correction amount C of the luminance of the image is the upper limit value C (1 )

  As a result, from time T (5) to time T (6), the brightness BL of the backlight 5 decreases with time, while the image brightness correction amount C increases.

  When a bright image is input as display data at time T (6), the target value of the brightness BL of the backlight 5 is the upper limit value BL (1), and the image brightness correction amount C is the lower limit value. It becomes the value C (0).

  As a result, from time T (6) to time T (7), the brightness BL of the backlight 5 increases with time until it reaches the upper limit value BL (1) at time T (7). . Further, the correction amount C of the luminance of the image decreases with time until it reaches the lower limit C (0) at time T (7).

  When the backlight brightness BL reaches the upper limit value BL (1) and the image brightness correction amount C reaches the lower limit value C (0) at time T (7), the brightness of the backlight 5 BL is maintained at the upper limit value BL (1), and the correction amount C of the luminance of the image is maintained at the lower limit value C (0).

  If a black image is input as display data at time T (8) and the brightness difference from the previous display data image is greater than a threshold value, it is determined that an unintended black image has been detected. (YES in S102). Since the counter value in the timer unit 38 has been initialized, counting is started (S104). Since the count does not stop until a predetermined time has elapsed since the count was started (NO in S108), the target value of the brightness BL of the backlight 5 immediately before detection of the black image becomes the current target value. The correction amount C of the luminance of the image immediately before detection of the black image is the current correction amount C.

  As a result, the brightness BL of the backlight 5 is maintained at the upper limit value BL (1), and the image brightness correction amount C is maintained at the lower limit value C (0).

  When a bright image is input as display data at time T (9) (NO in S100 and S102), the target value of the brightness BL of the backlight 5 becomes the upper limit value BL (1), and the brightness of the image Is the lower limit C (0).

  As a result, the brightness BL of the backlight 5 is maintained at the upper limit value BL (1), and the image brightness correction amount C is maintained at the lower limit value C (0).

  Therefore, after time T (7), the brightness BL of the backlight 5 and the correction amount C of the brightness of the image are maintained constant regardless of the detection of the unintended black image.

<When the present invention is not applied>
In FIG. 4, it is assumed that display data similar to that in FIG. 3 is input. Therefore, the change in the brightness BL of the backlight 5 and the change in the correction amount C of the brightness of the image from time T (1) to time T (7) in FIG. This is the same as the change in the luminance BL of the backlight 5 and the change in the correction amount C of the luminance of the image up to 7). Therefore, detailed description thereof will not be repeated.

  When the input display data is a black image at time T (8), the target value of the luminance BL of the backlight 5 is the lower limit value BL (0), and the correction amount C of the luminance of the image is The upper limit value C (1) is obtained.

  As a result, from time T (8) to time T (10), the brightness BL of the backlight 5 decreases with time, whereas the image brightness correction amount C increases. .

  When the brightness BL of the backlight 5 reaches the lower limit value BL (0) and the correction amount C of the brightness of the image reaches the upper limit value C (1) at time T (10) to T (11). The brightness BL of the backlight 5 and the correction amount C of the brightness of the image are maintained.

  When a bright image is input as display data at time T (11), the target value of the luminance BL of the backlight 5 is the upper limit value BL (1), and the correction amount C of the luminance of the image is the lower limit value. It becomes the value C (0).

  As a result, from time T (11) to time T (12), the brightness BL of the backlight 5 increases with time, while the image brightness correction amount C decreases. .

  Therefore, from the time T (8) to the time T (10), the luminance BL of the backlight 5 rapidly decreases from the upper limit value BL (1) to the lower limit value BL (0) due to the detection of an unintended black image. The correction amount C of the image brightness increases rapidly from the lower limit value C (0) to the upper limit value C (1).

  Thereafter, the display data is restored to a bright image from time T (11) to time T (12), whereby the brightness BL of the backlight 5 increases rapidly from the lower limit value BL (0) to the upper limit value BL (1). At the same time, the correction amount C of the brightness of the image rapidly decreases from the upper limit value C (1) to the lower limit value C (0). Such a large change in the luminance BL of the backlight 5 and the correction amount C of the luminance of the image causes flickering.

  As described above, according to the image display device 1 according to the present embodiment, when a plurality of images are continuously displayed and an unintended black image is detected in the plurality of images, the black image is displayed. Correction of the luminance of the backlight 5 and the luminance of the image is suppressed until a predetermined time has elapsed since the detection. Thereby, the change of the brightness | luminance BL of the backlight 5 and the brightness | luminance correction amount C resulting from the display of a black image can be suppressed. As a result, occurrence of flicker can be suppressed. Therefore, it is possible to provide an image display device that suppresses deterioration of display quality, a control method for the image display device, a control program for the image display device, and a recording medium on which the control program is recorded.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Image display apparatus, 2 Control apparatus, 3 Display driver, 4 Liquid crystal panel, 5 Backlight, 30 Image processing part, 32 Image analysis part, 34 Backlight control part, 36 Black image detection part, 38 Timer part

Claims (9)

A liquid crystal panel for displaying images;
A light source for illuminating the liquid crystal panel;
A controller for correcting the luminance of the light source and the luminance of the image,
In the case where a plurality of images are continuously displayed and the black image is detected from the plurality of images, the control device is configured to detect the light source until a predetermined time elapses after the black image is detected. An image display device that suppresses correction of luminance and luminance of the image.   When the control device displays the plurality of images continuously, the black image is detected, and the magnitude of the difference in brightness between the black image and the image detected immediately before is larger than a threshold value. 2. The image display device according to claim 1, wherein correction of luminance of the light source and luminance of the image is suppressed until the predetermined time elapses after the black image is detected.   The image according to claim 1, wherein the control device cancels suppression of correction of luminance of the light source and luminance of the image when detection of the black image continues for the predetermined time or longer. Display device.   The control device corrects to increase the luminance of the image while decreasing the luminance of the light source as the brightness of the image is small, and increases the luminance of the light source as the luminance is large. The image display device according to claim 1, wherein the correction is performed so as to reduce the luminance of the image.   The predetermined time is set so that flicker does not occur due to correction of luminance of the light source based on detection of the black image and luminance of the image. Image display device.   The image display device according to claim 1, wherein the control device determines whether the image is a black image based on a histogram of the image. A control method for an image display device, comprising: a liquid crystal panel that displays an image; and a light source that illuminates the liquid crystal panel,
Correcting the brightness of the light source and the brightness of the image;
In the case where a plurality of images are continuously displayed, when a black image is detected from the plurality of images, the brightness of the light source and the image of the image are detected until a predetermined time elapses after the black image is detected. A method for controlling the image display device, the step including suppressing the correction of luminance. A control program for an image display device including a liquid crystal panel for displaying an image and a light source for illuminating the liquid crystal panel,
The control program is stored in a computer.
Correcting the brightness of the light source and the brightness of the image;
In the case where a plurality of images are continuously displayed, when a black image is detected from the plurality of images, the brightness of the light source and the image of the image are detected until a predetermined time elapses after the black image is detected. A control program for an image display device, which executes a step of suppressing correction of luminance.   A recording medium on which the control program for the image display device according to claim 8 is recorded.

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